Optimized flagellin enhances systemic and mucosal immune responses induced by SARS-CoV-2 virus-like particle vaccines.

Restoring immunoglobulin A/polymeric immunoglobulin receptor transport axis for the oral treatment of inflammatory bowel disease.

de Morais Ferreira, AB, Halson, S, Galvão-Coelho, NL, de Almeida, RN, Nakamura, FY, and Mortatti, AL. Impact of sleep restriction and intensified training on mucosal immunity and psychological responses in young soccer players. J Strength Cond Res 40(7): e703-e713, 2026-This study analyzed the effects of training intensification during a period of sleep restriction (SR) on mucosal immunity (salivary IgA), upper respiratory tract health, mood states, and stress tolerance in young soccer players. Sixteen male youth soccer players completed 7 weeks of training with varied workloads. Weeks 3 and 5 involved a 75% increase in internal training load (ITL); however, although sleep was unrestricted in week 3, allowing for an increase in total sleep time (TST) (+53 minutes vs. baseline), week 5 included a ∼10% reduction in TST (-44 minutes vs. baseline). Internal training load was assessed using session-rating of perceived exertion, and sleep was monitored via actigraphy. Salivary IgA, upper respiratory tract infection (URTI) severity (Wisconsin Upper Respiratory Symptom Survey), perceived recovery status (PRS), stress tolerance (Daily Analysis of Life Demands of Athletes), and mood states (Brunel Mood Scale) were evaluated weekly. Salivary IgA concentrations significantly decreased in both intensified training weeks (week 3: β = -87.41, p = 0.007; week 5: β = -114.04, p < 0.001). However, only in week 5, this reduction was accompanied by a significant increase in URTI severity ( p = 0.001), heightened fatigue (χ 2 (6) = 42.499, p < 0.001), reduced vigor (χ 2 (6) = 49.422, p < 0.001), impaired PRS ( p < 0.001), and lower stress tolerance ( p = 0.001). In contrast, during week 3, despite the intensified training, PRS, mood states, and stress tolerance remained stable. These findings emphasize the protective role of adequate sleep during intensified training, as greater sleep availability in week 3 may have mitigated the negative effects observed in week 5. Ensuring sufficient sleep during periods of high training loads is essential to maintain physical and psychological health.

Teleost bone morphogenetic protein 2 (BMP2): Dynamic responses to infection and negative feedback regulation of inflammatory cytokines in gills of flounder (Paralichthys olivaceus).

Oral immunization with recombinant Lactococcus lactis expressing VP3 and VP3-IFNα fusion protein protects ducklings against novel goose parvovirus infection.

Development of a DC-targeting Salmonella- amplifying RNA vector platform co-delivering dual antigens and adjuvants for enhanced protection against H9N2 avian influenza.

Alteration characteristics of intestinal mucosal immunity and transcriptome in Songpu mirror carp (Cyprinus carpio Songpu) exposed to acute cadmium exposure

Phase 1 trial of intranasal NDV-HXP-S in previously vaccinated adults.

The role of mucosal IgA in protection against influenza A H1N1 virus infection in a real-world setting.

Gnotobiology, from the Greek gnotos (meaning 'known') and bios (meaning 'life'), is a research discipline that uses organisms with a defined microbiological status to study the interaction between hosts and microbes. This review traces six decades of Czech gnotobiology, beginning with the launch of a dedicated gnotobiology programme at Nový Hrádek in 1962 by Jaroslav Šterzl, whose visionary aims anticipated by decades the current recognition of the microbiota as a central determinant of immune and broader physiological function. The site - originally established in 1953 as the Biological Station - was thereby transformed into one of only four gnotobiological laboratories worldwide at that time and the first in Central and Eastern Europe. The facility pioneered the rearing of germ-free piglets, rats, rabbits, and mice, establishing the experimental foundation for the laboratory's work on immune ontogeny, mucosal immunity and tolerance, and microbiota-host interactions in immune development and regulation. This review discusses the key discoveries made using these models. Among them, work at the Institute of Microbiology (Prague and Nový Hrádek) demonstrated that germ-free animals have underdeveloped lymphoid tissue and impaired adaptive immunity. The review also describes the subsequent development of gnotobiotic models of human metabolic, immune-mediated, neoplastic, and neuropsychiatric diseases. The completion of the Human Genome Project in 2001 and the emergence of microbial metagenomics in the early 2000s sparked renewed interest in host-microbe interactions and led to a rediscovery of gnotobiotic approaches as essential tools for establishing causation in microbiome research. We examine how integrating these approaches with high-throughput sequencing, metabolomics, and other omics technologies has shifted the focus from cataloguing the microbiome to mechanistically dissecting host-microbe interactions. Finally, we outline future directions, including humanized gnotobiotic models, microbiota-based therapeutics, and the convergence of gnotobiology with personalized medicine and synthetic biology.

New Perspectives in the Research of Helicobacter pylori Vaccine.

Tissue-embedded CD4+ plasticity defines mucosal immunity in inflammatory bowel disease.

CD200R protects against ulcerative colitis by regulating macrophage polarization and intestinal barrier function: evidence from human patients and mouse disease models.

Pregnancy stages differentially impact maternal alveolar macrophages' function and immunity to SARS-CoV-2 infection.

The multifaceted ILC3s: Key regulator of mucosal defense and homeostasis.

The aryl hydrocarbon receptor (AHR) plays a central role in orchestrating gut barrier and mucosal immune functions in the pathogenesis of inflammatory bowel disease (IBD). Nevertheless, activation of the AHR by diverse ligands yields varied outcomes, and the downstream pathways responsible for these effects remain unknown. Here, we report that selective activation of AHR in mouse intestinal epithelial cells (IEC) by the microbial metabolite, urolithin A (UroA), triggers the Nod-like receptor pyrin domain-containing protein 6 (NLRP6) inflammasome, resulting in the release of interleukin (IL)-18 but not IL-1β. Further, we show that UroA-induced IL-18 in IECs is critical for IL-22, mucin 2 and REG3γ production, as well as protection against colitis. Moreover, UroA significantly upregulates IL-18 and IL-22 levels in IECs and type-3 innate lymphoid cells, respectively, in intestinal biopsies from patients with IBD patients. These results demonstrate that activation of AHR by UroA modulates intestinal barrier function through an NLRP6-IL-18-IL-22 pathway in both healthy and IBD conditions.

Mucosal surfaces are sites of highly dynamic interactions among epithelial and immune cells, environmental exposures, particularly dietary inputs, and the diverse microbial communities and their metabolites. These elements continually influence each other to maintain homeostasis and ensure appropriate immune discrimination between pathogens and innocuous stimuli, such as commensal microbes and dietary antigens. When this balance is disrupted, immune tolerance breaks down, leading to maladaptive responses characteristic of food allergy. Targeting mucosal interactions to restore homeostasis, therefore, holds substantial promise for preventing and treating food allergies and other atopic diseases. However, the complexity of the interconnected networks linking host factors, the microbiome, and diet presents major challenges. In this review, we synthesize recent advances in understanding the mechanisms governing mucosal crosstalk in both health and allergic disease. We provide an in-depth examination of the intestinal mucus layer and its components as active mediators of microbiota-host communication and potential initiators of allergic responses. We also discuss emerging mechanistic and therapeutic insights into how diet, food-derived molecules or treatments shape mucosal immunity, and highlight key knowledge gaps that warrant further investigation to clarify how disruptions in these interactions contribute to allergic sensitization.

AIRRWAS integrates TCR-microbiome data to reveal how the gut microbiome shapes the circulating and mucosal T cell repertoire.

Despite the widespread use of the BCG vaccine, tuberculosis remains a leading global health threat. The primary limitation of BCG lies in its failure to prevent pulmonary TB in adults, largely due to its systemic administration route which fails to induce robust mucosal immunity at the site of primary infection. This study evaluates a novel mucosal vaccine platform, TB-PCF, incorporating Mycobacterium tuberculosis antigens ESAT6 and CFP10 fused with Cholera Toxin B subunit (CTB) and an IgG-Fc domain to enhance polymerisation and antigen uptake by antigen-presenting cells. Following systemic priming and mucosal boosting in mice, TB-PCF vaccine elicited significant antigen-specific antibody responses in serum and bronchoalveolar lavage fluid, as well as polyfunctional systemic Th1 and Th17 responses, characterised by elevated IFN-γ and IL-17. Notably, splenocytes from vaccinated mice exhibited significant bacterial killing in a modified mycobacterial growth inhibition assay (MGIA), trending higher than BCG. However, in the subsequent in vivo challenge test, only the BCG-vaccinated group achieved a statistically significant reduction in lung bacterial burden. While the failure to translate in vitro bacterial killing into in vivo protection suggests that the ESAT6-CFP10 antigen duo may lack the necessary antigenic breadth for full protection, we propose that the TB-PCF platform is a promising, new tool for future screening of diverse antigen combinations to overcome current roadblocks in mucosal TB vaccination.

Selenium nanoparticles alleviate ulcerative colitis by regulating macrophage mitochondrial dynamics.